纳米羟基磷灰石/聚酰胺66颈前路减压后前方骨缺损仿生髂骨的制备及性能

Preparation and property of nano-hydroxyapatite/polyamide66 composites for ilium-grafting in bone defect following decompression

背景:在椎体和椎间盘切除以后,对于减压后前方骨缺损的修补长期以来以钛网和自身髂骨两种方式为主,但效果都不尽理想。目的:制备纳米羟基磷灰石/聚酰胺66复合材料,对其进行表征和生物力学性能检测。设计、时间及地点:重复性对比实验,于2008-01/12在南京航空航天大学材料科学与技术学院无机材料实验室完成。材料:利用水热反应法制备纳米羟基磷灰石晶体,通过液相混合、冷压烧结制备出纳米羟基磷灰石/聚酰胺66仿生骨块。方法:切除新鲜冰冻正常颈椎标本C5椎体,植入不同材料,钢板螺钉内固定,进行生物力学测试。具体分组为:正常颈椎组、纳米羟基磷灰石/聚酰胺66仿生髂骨钢板螺钉内固定组、髂骨植骨钢板螺钉内固定组。加载时模拟人体颈椎生理运动,即中心位、前屈位、后伸位和侧屈位4种生理情况。主要观察指标:①通过X射线衍射仪对材料的物相进行表征。②红外图谱对材料的基团构成进行表征。③扫描电镜观察仿生骨的端口形貌。④正常颈椎、仿生髂骨、髂骨植骨进行生物力学检测。结果:①X射线衍射结果表明纳米羟基磷灰石和聚酰胺66的主要衍射峰在复合材料中存在,但纳米羟基磷灰石对聚酰胺66的β晶型衍射峰起到宽化、削弱的作用。②红外图谱表明两者之间存在氢键。③扫描电镜观察,两者结合密实,界面性能优异。④通过生物力学实验,对比得出,仿生髂骨在载荷-应变变化、载荷-位移变化、应力强度方面都优于髂骨植骨,仅次于正常颈椎骨。结论:所制备的纳米羟基磷灰石/聚酰胺66仿生骨力学性能优异,是一种理想的颈椎替代材料。

BACKGROUND： After excision of vertebra and cervical intervertebral disc, repairs of bone defect after reducing pressure mainly have used titanium mesh and ilium for a long time, but the effect is not perfect. OBJECTIVE： To prepare nano-hydroxyapatite/polyamide66 （n-HA/PA66） composites, and to test the representation and biomechanical properties. DESIGN, TIME AND SETTING： A repeated and comparative study was performed at Laboratory of Inorganic Material, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics from January to December 2008. MATERIALS： Nano-hydroxyapatite crystal was prepared using hydrothermal reaction, and the nano-hydroxyapatite/polyamide66 of bone-grafting specimens was prepared by co-precipitation, cold-pressing and sintering. METHODS： Normal C5 samples were implanted into different materials and then internal-fixed using screw to test the biomechanics. The grouping was as following： normal cervical vertebra group, n-HA/PA66 ilium-grafting internal fixation group, and ilium-grafting internal fixation group. Physiological motion of cervical vertebra was simulate to human body at neutral, flexion extension and lateral-flexion positions. MAIN OUTCOM MEASURES： ① The phase of the composites was characterized by X-ray diffraction. ② The group of the composites was analyzed by infrared spectrum. ③ Scanning electron microscopy was used to analyze the scaffold of bone-grafting specimens. ④ The measurements of biomechanical properties were carried out with normal cervical specimens, bone-grafting specimens and the ilium-grafting specimens. RESULTS： ① X-ray diffraction results revealed that the main diffraction curves of nano-hydroxyapatite and polyamide66 remained in the composites, but n-HA would widen and weaken the 13 crystals in polyamide66. ② Infrared spectrum results showed that nano-hydroxyapatite and polyamide66 were mainly linked by hydrogen-bonding. ③ Scanning electron microscopy examined the scaffold of bone-grafting and revealed that the composites had tight combination and good interface. ④ The measurements of biomechanical properties indicated that the bone-grafting specimens had better performances in load-strain, load-displacement and stress intensity in comparison with ilium-grafting ones, only a little bit lower than the normal cervical vertebrae. CONCLUSION： The bone-grafting specimens have outstanding biomechanical properties and are an ideal kind of material to instead cervical vertebrae.